#include<stdlib.h>
#include<string.h>
#include<stdio.h>

 int main(int argc,char*argv[]){
const char *arg = argv[1];

   if(strcmp(arg, "-a")==0)
       printf("这是功能1\n");
   else if(strcmp(arg, "-b")==0)
       printf("这是功能2\n");
   else if(strcmp(arg, "-c")==0)
       printf("这是功能3\n");
   else
       printf("Usage: %s [-a|-b|-c]\n", argv[0]);
 }
